Many medical diagnoses rely on non-invasive diagnostic tools to provide information, usually in the form of images, descriptive of status of internal portions or organs of a patient. These tools include thermal imaging (e.g., mammography), ultrasonic probes, magnetic resonance imaging techniques, positron emission tomography, computed tomography (CT), single photon emission-computed tomography (SPECT), optical imaging and/or X-ray based techniques. In some instances, imaging aids, such as contrast-enhancing agents, are introduced into the subject or patient to aid in increasing available data content from the non-destructive or non-invasive imaging technique or techniques being employed.
Each of these tools presents advantages in particularized situations, has technological limitations, may require set-up and analysis time, can include risks and also has associated costs. As a result, a cost-benefit analysis that also reflects the urgency or lack thereof with respect to a particular diagnostic trajectory often favors usage of X-ray based measurement techniques.
However, exposure to X-rays can result in some risk to the test subject or patient. For at least this reason, the dosage of X-rays incident on the patient, organ or object being evaluated/imaged, is often carefully chosen and controlled, for example, by selecting an area to be exposed, current to the X-ray tube, peak voltage applied to the X-ray tube (kVp) and exposure time, to provide successful imaging, based on the task and the test subject or patient's parameters, with least health risk to the patient or radiation exposure to the object being imaged. The Food and Drug Administration has recently identified X-rays as potentially having carcinogenic effects, adding impetus to the desire to reduce overall exposure while still providing imaging characteristics capable of enabling rapid, effective and accurate diagnostic aids.
Several factors influence the Image Quality or IQ resulting from an X-ray procedure. Statistical photon noise resulting from characteristics of the X-ray source and the X-ray generation conditions tends to dominate other noise sources in formation of an X-ray image. Contrast between various image portions, and contrast enhancement techniques, are also important considerations in providing diagnostic images, and these issues require increasingly sophisticated treatment as dose and/or photon energy are decreased.
For the reasons stated above, and for other reasons discussed below, which will become apparent to those skilled in the art upon reading and understanding the present disclosure, there are needs in the art to provide test data in support of reliable diagnoses of medical conditions and diseases from medical anatomical images, providing contrast equal to or exceeding that of conventional approaches, yet using reduced exposure parameters when feasible, consistent with the imaging task.